@article{ZieglerEhlisWeberetal.2021,
  author    = {Ziegler, Georg C. and Ehlis, Ann-Christine and Weber, Heike and Vitale, Maria Rosaria and Z{\"o}ller, Johanna E. M. and Ku, Hsing-Ping and Schiele, Miriam A. and K{\"u}rbitz, Laura I. and Romanos, Marcel and Pauli, Paul and Kalisch, Raffael and Zwanzger, Peter and Domschke, Katharina and Fallgatter, Andreas J. and Reif, Andreas and Lesch, Klaus-Peter},
  title     = {A Common CDH13 Variant is Associated with Low Agreeableness and Neural Responses to Working Memory Tasks in ADHD},
  series = {Genes},
  volume    = {12},
  journal   = {Genes},
  number    = {9},
  issn      = {2073-4425},
  doi       = {10.3390/genes12091356},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245220},
  year      = {2021},
  abstract  = {The cell—cell signaling gene CDH13 is associated with a wide spectrum of neuropsychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD), autism, and major depression. CDH13 regulates axonal outgrowth and synapse formation, substantiating its relevance for neurodevelopmental processes. Several studies support the influence of CDH13 on personality traits, behavior, and executive functions. However, evidence for functional effects of common gene variation in the CDH13 gene in humans is sparse. Therefore, we tested for association of a functional intronic CDH13 SNP rs2199430 with ADHD in a sample of 998 adult patients and 884 healthy controls. The Big Five personality traits were assessed by the NEO-PI-R questionnaire. Assuming that altered neural correlates of working memory and cognitive response inhibition show genotype-dependent alterations, task performance and electroencephalographic event-related potentials were measured by n-back and continuous performance (Go/NoGo) tasks. The rs2199430 genotype was not associated with adult ADHD on the categorical diagnosis level. However, rs2199430 was significantly associated with agreeableness, with minor G allele homozygotes scoring lower than A allele carriers. Whereas task performance was not affected by genotype, a significant heterosis effect limited to the ADHD group was identified for the n-back task. Heterozygotes (AG) exhibited significantly higher N200 amplitudes during both the 1-back and 2-back condition in the central electrode position Cz. Consequently, the common genetic variation of CDH13 is associated with personality traits and impacts neural processing during working memory tasks. Thus, CDH13 might contribute to symptomatic core dysfunctions of social and cognitive impairment in ADHD.},
  language  = {en}
}
@article{ZayatsJacobsenKleppeetal.2016,
  author    = {Zayats, T and Jacobsen, KK and Kleppe, R and Jacob, CP and Kittel-Schneider, S and Ribas{\´e}s, M and Ramos-Quiroga, JA and Richarte, V and Casas, M and Mota, NR and Grevet, EH and Klein, M and Corominas, J and Bralten, J and Galesloot, T and Vasquez, AA and Herms, S and Forstner, AJ and Larsson, H and Breen, G and Asherson, P and Gross-Lesch, S and Lesch, KP and Cichon, S and Gabrielsen, MB and Holmen, OL and Bau, CHD and Buitelaar, J and Kiemeney, L and Faraone, SV and Cormand, B and Franke, B and Reif, A and Haavik, J and Johansson, S},
  title     = {Exome chip analyses in adult attention deficit hyperactivity disorder},
  series = {Translational Psychiatry},
  volume    = {6},
  journal   = {Translational Psychiatry},
  number    = {e923},
  doi       = {10.1038/tp.2016.196},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168297},
  year      = {2016},
  abstract  = {Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable childhood-onset neuropsychiatric condition, often persisting into adulthood. The genetic architecture of ADHD, particularly in adults, is largely unknown. We performed an exome-wide scan of adult ADHD using the Illumina Human Exome Bead Chip, which interrogates over 250 000 common and rare variants. Participants were recruited by the International Multicenter persistent ADHD CollaboraTion (IMpACT). Statistical analyses were divided into 3 steps: (1) gene-level analysis of rare variants (minor allele frequency (MAF)<1\%); (2) single marker association tests of common variants (MAF⩾1\%), with replication of the top signals; and (3) pathway analyses. In total, 9365 individuals (1846 cases and 7519 controls) were examined. Replication of the most associated common variants was attempted in 9847 individuals (2077 cases and 7770 controls) using fixed-effects inverse variance meta-analysis. With a Bonferroni-corrected significance level of 1.82E-06, our analyses of rare coding variants revealed four study-wide significant loci: 6q22.1 locus (P=4.46E-08), where NT5DC1 and COL10A1 reside; the SEC23IP locus (P=6.47E-07); the PSD locus (P=7.58E-08) and ZCCHC4 locus (P=1.79E-06). No genome-wide significant association was observed among the common variants. The strongest signal was noted at rs9325032 in PPP2R2B (odds ratio=0.81, P=1.61E-05). Taken together, our data add to the growing evidence of general signal transduction molecules (NT5DC1, PSD, SEC23IP and ZCCHC4) having an important role in the etiology of ADHD. Although the biological implications of these findings need to be further explored, they highlight the possible role of cellular communication as a potential core component in the development of both adult and childhood forms of ADHD.},
  language  = {en}
}
@article{SchaeferFriedrichJorgensenetal.2018,
  author    = {Sch{\"a}fer, Nadine and Friedrich, Maximilian and J{\o}rgensen, Morten Egevang and Kollert, Sina and Koepsell, Hermann and Wischmeyer, Erhard and Lesch, Klaus-Peter and Geiger, Dietmar and D{\"o}ring, Frank},
  title     = {Functional analysis of a triplet deletion in the gene encoding the sodium glucose transporter 3, a potential risk factor for ADHD},
  series = {PLoS ONE},
  volume    = {13},
  journal   = {PLoS ONE},
  number    = {10},
  doi       = {10.1371/journal.pone.0205109},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176495},
  pages     = {e0205109},
  year      = {2018},
  abstract  = {Sodium-glucose transporters (SGLT) belong to the solute carrier 5 family, which is characterized by sodium dependent transport of sugars and other solutes. In contrast, the human SGLT3 (hSGLT3) isoform, encoded by SLC5A4, acts as a glucose sensor that does not transport sugar but induces membrane depolarization by Na\(^{+}\) currents upon ligand binding. Whole-exome sequencing (WES) of several extended pedigrees with high density of attention-deficit/hyperactivity disorder (ADHD) identified a triplet ATG deletion in SLC5A4 leading to a single amino acid loss (ΔM500) in the hSGLT3 protein imperfectly co-segregating with the clinical phenotype of ADHD. Since mutations in homologous domains of hSGLT1 and hSGLT2 were found to affect intestinal and renal function, respectively, we analyzed the functional properties of hSGLT3[wt] and [ΔM500] by voltage clamp and current clamp recordings from cRNA-injected Xenopus laevis oocytes. The cation conductance of hSGLT3[wt] was activated by application of glucose or the specific agonist 1-desoxynojirimycin (DNJ) as revealed by inward currents in the voltage clamp configuration and cell depolarization in the current clamp mode. Almost no currents and changes in membrane potential were observed when glucose or DNJ were applied to hSGLT3[ΔM500]-injected oocytes, demonstrating a loss of function by this amino acid deletion in hSGLT3. To monitor membrane targeting of wt and mutant hSGLT3, fusion constructs with YFP were generated, heterologously expressed in Xenopus laevis oocytes and analyzed for membrane fluorescence by confocal microscopy. In comparison to hSGLT3[wt] the fluorescent signal of mutant [ΔM500] was reduced by 43\% indicating that the mutant phenotype might mainly result from inaccurate membrane targeting. As revealed by homology modeling, residue M500 is located in TM11 suggesting that in addition to the core structure (TM1-TM10) of the transporter, the surrounding TMs are equally crucial for transport/sensor function. In conclusion, our findings indicate that the deletion [ΔM500] in hSGLT3 inhibits membrane targeting and thus largely disrupts glucose-induced sodium conductance, which may, in interaction with other ADHD risk-related gene variants, influence the risk for ADHD in deletion carriers.},
  language  = {en}
}
@article{PalladinoChiocchettiFranketal.2020,
  author    = {Palladino, Viola Stella and Chiocchetti, Andreas G. and Frank, Lukas and Haslinger, Denise and McNeill, Rhiannon and Radtke, Franziska and Till, Andreas and Haupt, Simone and Br{\"u}stle, Oliver and G{\"u}nther, Katharina and Edenhofer, Frank and Hoffmann, Per and Reif, Andreas and Kittel-Schneider, Sarah},
  title     = {Energy metabolism disturbances in cell models of PARK2 CNV carriers with ADHD},
  series = {Journal of Clinical Medicine},
  volume    = {9},
  journal   = {Journal of Clinical Medicine},
  number    = {12},
  issn      = {2077-0383},
  doi       = {10.3390/jcm9124092},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-220074},
  year      = {2020},
  abstract  = {The main goal of the present study was the identification of cellular phenotypes in attention-deficit-/hyperactivity disorder (ADHD) patient-derived cellular models from carriers of rare copy number variants (CNVs) in the PARK2 locus that have been previously associated with ADHD. Human-derived fibroblasts (HDF) were cultured and human-induced pluripotent stem cells (hiPSC) were reprogrammed and differentiated into dopaminergic neuronal cells (mDANs). A series of assays in baseline condition and in different stress paradigms (nutrient deprivation, carbonyl cyanide m-chlorophenyl hydrazine (CCCP)) focusing on mitochondrial function and energy metabolism (ATP production, basal oxygen consumption rates, reactive oxygen species (ROS) abundance) were performed and changes in mitochondrial network morphology evaluated. We found changes in PARK2 CNV deletion and duplication carriers with ADHD in PARK2 gene and protein expression, ATP production and basal oxygen consumption rates compared to healthy and ADHD wildtype control cell lines, partly differing between HDF and mDANs and to some extent enhanced in stress paradigms. The generation of ROS was not influenced by the genotype. Our preliminary work suggests an energy impairment in HDF and mDAN cells of PARK2 CNV deletion and duplication carriers with ADHD. The energy impairment could be associated with the role of PARK2 dysregulation in mitochondrial dynamics.},
  language  = {en}
}
@article{McNeillZieglerRadtkeetal.2020,
  author    = {McNeill, Rhiannon V. and Ziegler, Georg C. and Radtke, Franziska and Nieberler, Matthias and Lesch, Klaus‑Peter and Kittel‑Schneider, Sarah},
  title     = {Mental health dished up — the use of iPSC models in neuropsychiatric research},
  series = {Journal of Neural Transmission},
  volume    = {127},
  journal   = {Journal of Neural Transmission},
  issn      = {0300-9564},
  doi       = {10.1007/s00702-020-02197-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235666},
  pages     = {1547-1568},
  year      = {2020},
  abstract  = {Genetic and molecular mechanisms that play a causal role in mental illnesses are challenging to elucidate, particularly as there is a lack of relevant in vitro and in vivo models. However, the advent of induced pluripotent stem cell (iPSC) technology has provided researchers with a novel toolbox. We conducted a systematic review using the PRISMA statement. A PubMed and Web of Science online search was performed (studies published between 2006-2020) using the following search strategy: hiPSC OR iPSC OR iPS OR stem cells AND schizophrenia disorder OR personality disorder OR antisocial personality disorder OR psychopathy OR bipolar disorder OR major depressive disorder OR obsessive compulsive disorder OR anxiety disorder OR substance use disorder OR alcohol use disorder OR nicotine use disorder OR opioid use disorder OR eating disorder OR anorexia nervosa OR attention-deficit/hyperactivity disorder OR gaming disorder. Using the above search criteria, a total of 3515 studies were found. After screening, a final total of 56 studies were deemed eligible for inclusion in our study. Using iPSC technology, psychiatric disease can be studied in the context of a patient's own unique genetic background. This has allowed great strides to be made into uncovering the etiology of psychiatric disease, as well as providing a unique paradigm for drug testing. However, there is a lack of data for certain psychiatric disorders and several limitations to present iPSC-based studies, leading us to discuss how this field may progress in the next years to increase its utility in the battle to understand psychiatric disease.},
  language  = {en}
}
@article{JarickVolckmarPuetteretal.2014,
  author    = {Jarick, I. and Volckmar, A. L. and P{\"u}tter, C. and Pechlivanis, S. and Nguyen, T. T. and Dauvermann, M. R. and Beck, S. and Albayrak, {\"O}. and Scherag, S. and Gilsbach, S. and Cichon, S. and Hoffmann, P. and Degenhardt, F. and N{\"o}then, M. M. and Schreiber, S. and Wichmann, H. E. and J{\"o}ckel, K. H. and Heinrich, J. and Tiesler, C. M. T. and Faraone, S. V. and Walitza, S. and Sinzig, J. and Freitag, C. and Meyer, J. and Herpertz-Dahlmann, B. and Lehmkuhl, G. and Renner, T. J. and Warnke, A. and Romanos, M. and Lesch, K. P. and Reif, A. and Schimmelmann, B. G. and Hebebrand, J. and Scherag, A. and Hinney, A.},
  title     = {Genome-wide analysis of rare copy number variations reveals PARK2 as a candidate gene for attention-deficit/hyperactivity disorder},
  series = {Molecular Psychiatry},
  volume    = {19},
  journal   = {Molecular Psychiatry},
  number    = {19},
  doi       = {10.1038/mp.2012.161},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121131},
  pages     = {115-21},
  year      = {2014},
  abstract  = {Attention-deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurodevelopmental disorder. Genetic loci have not yet been identified by genome-wide association studies. Rare copy number variations (CNVs), such as chromosomal deletions or duplications, have been implicated in ADHD and other neurodevelopmental disorders. To identify rare (frequency ≤1\%) CNVs that increase the risk of ADHD, we performed a whole-genome CNV analysis based on 489 young ADHD patients and 1285 adult population-based controls and identified one significantly associated CNV region. In tests for a global burden of large (>500 kb) rare CNVs, we observed a nonsignificant (P=0.271) 1.126-fold enriched rate of subjects carrying at least one such CNV in the group of ADHD cases. Locus-specific tests of association were used to assess if there were more rare CNVs in cases compared with controls. Detected CNVs, which were significantly enriched in the ADHD group, were validated by quantitative (q)PCR. Findings were replicated in an independent sample of 386 young patients with ADHD and 781 young population-based healthy controls. We identified rare CNVs within the parkinson protein 2 gene (PARK2) with a significantly higher prevalence in ADHD patients than in controls \((P=2.8 × 10^{-4})\) after empirical correction for genome-wide testing). In total, the PARK2 locus (chr 6: 162 659 756-162 767 019) harboured three deletions and nine duplications in the ADHD patients and two deletions and two duplications in the controls. By qPCR analysis, we validated 11 of the 12 CNVs in ADHD patients \((P=1.2 × 10^{-3})\) after empirical correction for genome-wide testing). In the replication sample, CNVs at the PARK2 locus were found in four additional ADHD patients and one additional control \((P=4.3 × 10^{-2})\). Our results suggest that copy number variants at the PARK2 locus contribute to the genetic susceptibility of ADHD. Mutations and CNVs in PARK2 are known to be associated with Parkinson disease.},
  language  = {en}
}
@article{JanschGuentherWaideretal.2018,
  author    = {Jansch, Charline and G{\"u}nther, Katharina and Waider, Jonas and Ziegler, Georg C. and Forero, Andrea and Kollert, Sina and Svirin, Evgeniy and P{\"u}hringer, Dirk and Kwok, Chee Keong and Ullmann, Reinhard and Maierhofer, Anna and Flunkert, Julia and Haaf, Thomas and Edenhofer, Frank and Lesch, Klaus-Peter},
  title     = {Generation of a human induced pluripotent stem cell (iPSC) line from a 51-year-old female with attention-deficit/hyperactivity disorder (ADHD) carrying a duplication of SLC2A3},
  series = {Stem Cell Research},
  volume    = {28},
  journal   = {Stem Cell Research},
  doi       = {10.1016/j.scr.2018.02.005},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176654},
  pages     = {136-140},
  year      = {2018},
  abstract  = {Fibroblasts were isolated from a skin biopsy of a clinically diagnosed 51-year-old female attention-deficit/hyperactivity disorder (ADHD) patient carrying a duplication of SLC2A3, a gene encoding neuronal glucose transporter-3 (GLUT3). Patient fibroblasts were infected with Sendai virus, a single-stranded RNA virus, to generate transgene-free human induced pluripotent stem cells (iPSCs). SLC2A3-D2-iPSCs showed expression of pluripotency-associated markers, were able to differentiate into cells of the three germ layers in vitro and had a normal female karyotype. This in vitro cellular model can be used to study the role of risk genes in the pathogenesis of ADHD, in a patient-specific manner.},
  language  = {en}
}
@article{JainVelezAcostaetal.2012,
  author    = {Jain, M. and V{\´e}lez, J. I. and Acosta, M. T. and Palacio, L. G. and Balog, J. and Roessler, E. and Pineda, D. and Londo{\~n}o, A. C. and Palacio, J. D. and Arbelaez, A. and Lopera, F. and Elia, J. and Hakonarson, H. and Seitz, C. and Freitag, C. M. and Palmason, H. and Meyer, J. and Romanos, M. and Walitza, S. and Hemminger, U. and Warnke, A. and Romanos, J. and Renner, T. and Jacob, C. and Lesch, K.-P. and Swanson, J. and Castellanos, F. X. and Bailey-Wilson, J. E. and Arcos-Burgos, M. and Muenke, M.},
  title     = {A cooperative interaction between LPHN3 and 11q doubles the risk for ADHD},
  series = {Molecular Psychiatry},
  volume    = {17},
  journal   = {Molecular Psychiatry},
  doi       = {10.1038/mp.2011.59},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125128},
  pages     = {741-747},
  year      = {2012},
  abstract  = {In previous studies of a genetic isolate, we identified significant linkage of attention deficit hyperactivity disorder (ADHD) to 4q, 5q, 8q, 11q and 17p. The existence of unique large size families linked to multiple regions, and the fact that these families came from an isolated population, we hypothesized that two-locus interaction contributions to ADHD were plausible. Several analytical models converged to show significant interaction between 4q and 11q (P<1 × 10-8) and 11q and 17p (P<1 × 10-6). As we have identified that common variants of the LPHN3 gene were responsible for the 4q linkage signal, we focused on 4q-11q interaction to determine that single-nucleotide polymorphisms (SNPs) harbored in the LPHN3 gene interact with SNPs spanning the 11q region that contains DRD2 and NCAM1 genes, to double the risk of developing ADHD. This interaction not only explains genetic effects much better than taking each of these loci effects by separated but also differences in brain metabolism as depicted by proton magnetic resonance spectroscopy data and pharmacogenetic response to stimulant medication. These findings not only add information about how high order genetic interactions might be implicated in conferring susceptibility to develop ADHD but also show that future studies of the effects of genetic interactions on ADHD clinical information will help to shape predictive models of individual outcome.},
  language  = {en}
}
@article{GrimmWeberKittelSchneideretal.2020,
  author    = {Grimm, Oliver and Weber, Heike and Kittel-Schneider, Sarah and Kranz, Thorsten M. and Jacob, Christian P. and Lesch, Klaus-Peter and Reif, Andreas},
  title     = {Impulsivity and Venturesomeness in an Adult ADHD Sample: Relation to Personality, Comorbidity, and Polygenic Risk},
  series = {Frontiers in Psychiatry},
  volume    = {11},
  journal   = {Frontiers in Psychiatry},
  issn      = {1664-0640},
  doi       = {10.3389/fpsyt.2020.557160},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219751},
  year      = {2020},
  abstract  = {While impulsivity is a basic feature of attention-deficit/hyperactivity disorder (ADHD), no study explored the effect of different components of the Impulsiveness (Imp) and Venturesomeness (Vent) scale (IV7) on psychiatric comorbidities and an ADHD polygenic risk score (PRS). We used the IV7 self-report scale in an adult ADHD sample of 903 patients, 70\% suffering from additional comorbid disorders, and in a subsample of 435 genotyped patients. Venturesomeness, unlike immediate Impulsivity, is not specific to ADHD. We consequently analyzed the influence of Imp and Vent also in the context of a PRS on psychiatric comorbidities of ADHD. Vent shows a distinctly different distribution of comorbidities, e.g., less anxiety and depression. PRS showed no effect on different ADHD comorbidities, but correlated with childhood hyperactivity. In a complementary analysis using principal component analysis with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition ADHD criteria, revised NEO Personality Inventory, Imp, Vent, and PRS, we identified three ADHD subtypes. These are an impulsive-neurotic type, an adventurous-hyperactive type with a stronger genetic component, and an anxious-inattentive type. Our study thus suggests the importance of adventurousness and the differential consideration of impulsivity in ADHD. The genetic risk is distributed differently between these subtypes, which underlines the importance of clinically motivated subtyping. Impulsivity subtyping might give insights into the organization of comorbid disorders in ADHD and different genetic background.},
  language  = {en}
}
@article{GeisslerJansBanaschewskietal.2018,
  author    = {Geissler, Julia and Jans, Thomas and Banaschewski, Tobias and Becker, Katja and Renner, Tobias and Brandeis, Daniel and D{\"o}pfner, Manfred and Dose, Christina and Hautmann, Christopher and Holtmann, Martin and Jenkner, Carolin and Millenet, Sabina and Romanos, Marcel},
  title     = {Individualised short-term therapy for adolescents impaired by attention-deficit/hyperactivity disorder despite previous routine care treatment (ESCAadol)-Study protocol of a randomised controlled trial within the consortium ESCAlife},
  series = {Trials},
  volume    = {19},
  journal   = {Trials},
  number    = {254},
  doi       = {10.1186/s13063-018-2635-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176061},
  year      = {2018},
  abstract  = {Background: Despite the high persistence rate of attention-deficit/hyperactivity disorder (ADHD) throughout the lifespan, there is a considerable gap in knowledge regarding effective treatment strategies for adolescents with ADHD. This group in particular often shows substantial psychosocial impairment, low compliance and insufficient response to psychopharmacological interventions. Effective and feasible treatments should further consider the developmental shift in ADHD symptoms, comorbidity and psychosocial adversity as well as family dysfunction. Thus, individualised interventions for adolescent ADHD should comprise a multimodal treatment strategy. The randomised controlled ESCAadol study addresses the needs of this patient group and compares the outcome of short-term cognitive behavioural therapy with parent-based telephone-assisted self-help. Methods/design: In step 1, 160 adolescents aged 12 to 17 years with a diagnosis of ADHD will undergo a treatment as usual (TAU) observation phase of 1 month. In step 2, those still severely affected are randomised to the intervention group with an Individualised Modular Treatment Programme (IMTP) or a telephone-assisted self-help programme for parents (TASH) as an active control condition. The IMTP was specifically designed for the needs of adolescent ADHD. It comprises 10 sessions of individual cognitive behavioural therapy with the adolescents and/or the parents, for which participants choose three out of 10 available focus modules (e.g. organisational skills and planning, emotion regulation, problem solving and stress management, dysfunctional family communication). TASH combines a bibliotherapeutic component with 10 counselling sessions for the parents via telephone. Primary outcome is the change in ADHD symptoms in a clinician-rated diagnostic interview. Outcomes are assessed at inclusion into the study, after the TAU phase, after the intervention phase and after a further 12-week follow-up period. The primary statistical analysis will be by intention-to-treat, using linear regression models. Additionally, we will analyse psychometric and biological predictors and moderators of treatment response. Discussion: ESCAadol compares two short-term non-pharmacological interventions as cost-efficient and feasible treatment options for adolescent ADHD, addressing the specific needs and obstacles to treatment success in this group. We aim to contribute to personalised medicine for adolescent ADHD intended to be implemented in routine clinical care.},
  language  = {en}
}